<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>login</title>
</head>
<body>
<form action="./servlet.do">
    username<input type="text" name="username"><br>
    hobby
    <input type="checkbox" name="hobby" value="c">c
    <input type="checkbox" name="hobby" value="c++">c++
    <input type="checkbox" name="hobby" value="c#">c#
    <input type="checkbox" name="hobby" value="java">Java
    <br>
    <button type="submit">000</button>
</form>
</body>
</html>